PURIFICATION OF NERVE GROWTH FACTOR ANTIBODIES BY AFFINITY CHROMATOGRAPHY

Pure antibodies to nerve growth factor have been isolated from sheep nerve growth factorantiserum by affinity chromatography using 2.5 S nerve growth factor linked to Sepharose 4B by means of cyanogen bromide. The elution of the antibodies was accomplished either at low pH (pH 2) or by high salt concentration (4.5 wMgC12). The purity of the antibodies was established by SDS-gel electrophoresis. Their immunological activity was tested by imrnunoprecipitation and their biological activity in a tissue culture assay using embryonic chick dorsal root ganglia.     

Temporal variations and pond age effect on plankton communities in semi-intensive freshwater marron (Cherax cainii,Austin and Ryan, 2002) earthen aquaculture ponds in Western Australia

The abundance and diversity of the plankton community represents the health of the aquatic ecosystem, and plays an important role in the growth of cultured animals under aquaculture conditions. The temporal variations of plankton abundance, taxonomic composition, diversity, evenness and species richness were studied in three old and three new semi-intensive marron (Cherax cainii, Austin and Ryan, 2002) ponds. Water parameters such as temperature, dissolved oxygen, pH, turbidity, TAN, nitrite, nitrate and reactive phosphate were recorded, and plankton samples were collected every two months, for one year of juvenile production cycle. A total of twenty-six phytoplankton and seven zooplankton genera were recorded. Chlorophyceae was the dominant class of phytoplankton throughout the year, followed by Trebouxiophyceae. Rotifera comprised 49.8% of the total zooplankton community (individuals L^?1), the largest proportion of any group. Temporal variations impacted the plankton abundance and community structure, and plankton abundance were more abundant during summer. The pond age did not influence the phytoplankton abundance, whereas zooplankton abundance was higher in older ponds.     

The effects of zinc oxide nanoparticles on the metallome in freshwater mussels

The use of zinc oxide nanoparticles (nanoZnO) as sunscreens has raised concerns about their safety and release in the aquatic environment through swimming activities and within municipally treated wastewaters. This study's purpose was to examine the effects of nanoZnO on the elemental composition (metallome) in exposed freshwater mussels, Elliptio complanata. Mussels were exposed for 21 days to an environmentally realistic (low) concentration (2 μg/L) of nanoZnO and zinc chloride. The mussels were also exposed to a physically and chemically treated municipal effluent (ME), both alone and in the presence of both forms of Zn. The metallome profile was characterized by the following 15 elements in gills, digestive gland and gonad tissues: Ag, Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, V and Zn. The levels of metallothioneins (MT) and lipid peroxidation (LPO) in the digestive gland were also measured as biomarkers of toxic effects. The data revealed that exposure to nanoZnO increased the total levels of Zn, MT and LPO in the digestive gland. Discriminate function analysis revealed that the digestive gland responded the most to exposure to either nanoZnO or Zn^2 +. For nanoZnO, the observed changes in Al, As and Mo in the digestive gland offered the best discrimination from dissolved Zn^2 +. Co-exposure of nanoZnO with the ME changed the metallome profile closer to dissolved Zn^2 +, suggesting a common interaction site within the ME. This was observed in changes in Ni, Cu, Se and Zn in the digestive gland of exposed mussels. Canonical analysis of essential and non-essential elements revealed that exposure to nanoZnO increased the relationships between LPO and the sum of essential elements in the digestive gland. Conversely, exposure to dissolved Zn^2 + and the ME decreased the relationship between the sum of non-essential elements and LPO and MT. In conclusion, the use of a “metallomic” approach was used to discriminate changes following exposure to nanoZnO and dissolved Zn in freshwater mussels and provided insights into the interaction of forms of Zn in ME towards mussels.     

Age-Specific Mortality During the 1918 Influenza Pandemic: Unravelling the Mystery of High Young Adult Mortality

The worldwide spread of a novel influenza A (H1N1) virus in 2009 showed that influenza remains a significant health threat, even for individuals in the prime of life. This paper focuses on the unusually high young adult mortality observed during the Spanish flu pandemic of 1918. Using historical records from Canada and the U.S., we report a peak of mortality at the exact age of 28 during the pandemic and argue that this increased mortality resulted from an early life exposure to influenza during the previous Russian flu pandemic of 1889–90. We posit that in specific instances, development of immunological memory to an influenza virus strain in early life may lead to a dysregulated immune response to antigenically novel strains encountered in later life, thereby increasing the risk of death. Exposure during critical periods of development could also create holes in the T cell repertoire and impair fetal maturation in general, thereby increasing mortality from infectious diseases later in life. Knowledge of the age-pattern of susceptibility to mortality from influenza could improve crisis management during future influenza pandemics.

“The war is over – and I must go” Egon Schiele, 1890–1918.

     

Anthranilic acid-based Thumb Pocket 2 HCV NS5B polymerase inhibitors with sub-micromolar potency in the cell-based replicon assay

Optimization efforts on the anthranilic acid-based Thumb Pocket 2 HCV NS5B polymerase inhibitors 1 and 2 resulted in the identification of multiple structural elements that contributed to improved cell culture potency. The additive effect of these elements resulted in compound 46, an inhibitor with enzymatic (IC₅₀) and cell culture (EC₅₀) potencies of less than 100 nanomolar.     

Cardio-Metabolic Disease Risks and Their Associations with Circulating 25-Hydroxyvitamin D and Omega-3 Levels in South Asian and White Canadians

Objectives

This study compared cardio-metabolic disease risk factors and their associations with serum vitamin D and omega-3 status in South Asian (SAC) and White Canadians (WC) living in Canada’s capital region.

Methods

Fasting blood samples were taken from 235 SAC and 279 WC aged 20 to 79 years in Ottawa, and 22 risk factors were measured.

Results

SAC men and women had significantly higher fasting glucose, insulin, homeostasis model assessment for insulin resistance (HOMA-IR), apolipoprotein B (ApoB), ratios of total (TC) to HDL cholesterol (HDLC) and ApoB to ApoA1, leptin, E-selectin, P-selectin, ICAM-1 and omega-3 (p < 0.05), but lower HDLC, ApoA1, vitamin D levels than WC (p < 0.05). SAC women had higher CRP and VEGF than WC women. Adequate (50–74.9 nmol/L) or optimal (≥ 75 nmol/L) levels of 25(OH)D were associated with lower BMI, glucose, insulin, HOMA-IR, TG, TC, low density lipoprotein cholesterol (LDLC), ApoB/ApoA1 ratio, CRP, leptin, and higher HDLC, ApoA1, omega-3 index, L-selectin levels in WC, but not in SAC. Intermediate (>4%-<8%) or high (≥ 8%) levels of omega-3 indices were related to lower E-selectin, P-selectin, ICAM-1 and higher HDLC, 25(OH)D levels in WC, but not in SAC. The BMIs of ≤ 25 kg/m² were related to lower LDLC, ApoB, VEGF, creatinine and higher 25(OH)D in WC, but not in SAC.

Conclusions

The associations of vitamin D, omega-3 status, BMI and risk factors were more profound in the WC than SAC. Compared to WC, vitamin D status and omega-3 index may not be good predictive risk factors for the prevalence of CVD and diabetes in SAC.     

Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements

When a laser is mode-locked, it emits a train of ultra-short pulses at a repetition rate determined by the laser cavity length. This article outlines a new and inexpensive procedure to force mode locking in a pre-adjusted nonlinear polarization rotation fiber laser. This procedure is based on the detection of a sudden change in the output polarization state when mode locking occurs. This change is used to command the alignment of the intra-cavity polarization controller in order to find mode-locking conditions. More specifically, the value of the first Stokes parameter varies when the angle of the polarization controller is swept and, moreover, it undergoes an abrupt variation when the laser enters the mode-locked state. Monitoring this abrupt variation provides a practical easy-to-detect signal that can be used to command the alignment of the polarization controller and drive the laser towards mode locking. This monitoring is achieved by feeding a small portion of the signal to a polarization analyzer measuring the first Stokes parameter. A sudden change in the read out of this parameter from the analyzer will occur when the laser enters the mode-locked state. At this moment, the required angle of the polarization controller is kept fixed. The alignment is completed. This procedure provides an alternate way to existing automating procedures that use equipment such as an optical spectrum analyzer, an RF spectrum analyzer, a photodiode connected to an electronic pulse-counter or a nonlinear detecting scheme based on two-photon absorption or second harmonic generation. It is suitable for lasers mode locked by nonlinear polarization rotation. It is relatively easy to implement, it requires inexpensive means, especially at a wavelength of 1550 nm, and it lowers the production and operation costs incurred in comparison to the above-mentioned techniques.     

No evidence of inbreeding depression in fast declining herds of migratory caribou

Identifying inbreeding depression early in small and declining populations is essential for management and conservation decisions. Correlations between heterozygosity and fitness (HFCs) provide a way to identify inbreeding depression without prior knowledge of kinship among individuals. In Northern Quebec and Labrador, the size of two herds of migratory caribou (Rivière‐George, RG and Rivière‐aux‐Feuilles, RAF) has declined by one to two orders of magnitude in the last three decades. This raises the question of a possible increase in inbreeding depression originating from, and possibly contributing to, the demographic decline in those populations. Here, we tested for the association of genomic inbreeding indices (estimated with 22,073 SNPs) with body mass and survival in 400 caribou sampled in RG and RAF herds between 1996 and 2016. We found no association of individual heterozygosity or inbreeding coefficient with body mass or annual survival. Furthermore, those genomic inbreeding indices remained stable over the period monitored. These results suggest that the rapid and intense demographic decline of the herds did not cause inbreeding depression in those populations. Although we found no evidence for HFCs, if demographic decline continues, it is possible that such inbreeding depression would be triggered.